docs: fix COLO architecture diagram

Fix COLO-Proxy part of COLO architecture diagram
Signed-off-by: NZhang Chen <zhangchen.fnst@cn.fujitsu.com>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>

docs/COLO-FT.txt

@@ -41,41 +41,43 @@ identical responses to all client requests. Once the differences in the outputs
 are detected between the PVM and SVM, COLO withholds transmission of the
 outbound packets until it has successfully synchronized the PVM state to the SVM.
 
-   Primary Node                                                            Secondary Node
- +------------+  +-----------------------+       +------------------------+  +------------+
- |            |  |       HeartBeat       |<----->|       HeartBeat        |  |            |
- | Primary VM |  +-----------|-----------+       +-----------|------------+  |Secondary VM|
- |            |              |                               |               |            |
- |            |  +-----------|-----------+       +-----------|------------+  |            |
- |            |  |QEMU   +---v----+      |       |QEMU  +----v---+        |  |            |
- |            |  |       |Failover|      |       |      |Failover|        |  |            |
- |            |  |       +--------+      |       |      +--------+        |  |            |
- |            |  |   +---------------+   |       |   +---------------+    |  |            |
- |            |  |   | VM Checkpoint |-------------->| VM Checkpoint |    |  |            |
- |            |  |   +---------------+   |       |   +---------------+    |  |            |
- |            |  |                       |       |                        |  |            |
- |Requests<---------------------------^------------------------------------------>Requests|
- |Responses----------------------\ /--|--------------\  /------------------------Responses|
- |            |  |               | |  |  |       |   |  |                 |  |            |
- |            |  | +-----------+ | |  |  |       |   |  |  +------------+ |  |            |
- |            |  | | COLO disk | | |  |  |       |   |  |  | COLO disk  | |  |            |
- |            |  | |   Manager |-|-|--|--------------|--|->| Manager    | |  |            |
- |            |  | +|----------+ | |  |  |       |   |  |  +-----------|+ |  |            |
- |            |  |  |            | |  |  |       |   |  |              |  |  |            |
- +------------+  +--|------------|-|--|--+       +---|--|--------------|--+  +------------+
-                    |            | |  |              |  |              |
- +-------------+    | +----------v-v--|--+       +---|--v-----------+  |    +-------------+
- |  VM Monitor |    | |  COLO Proxy      |       |    COLO Proxy    |  |    | VM Monitor  |
- |             |    | |(compare packet)  |       | (adjust sequence)|  |    |             |
- +-------------+    | +----------|----^--+       +------------------+  |    +-------------+
-                    |            |    |                                |
- +------------------|------------|----|--+       +---------------------|------------------+
- |   Kernel         |            |    |  |       |   Kernel            |                  |
- +------------------|------------|----|--+       +---------------------|------------------+
-                    |            |    |                                |
-     +--------------v+  +--------v----|--+       +------------------+ +v-------------+
-     |   Storage     |  |External Network|       | External Network | |   Storage    |
-     +---------------+  +----------------+       +------------------+ +--------------+
+  Primary Node                                                            Secondary Node
++------------+  +-----------------------+       +------------------------+  +------------+
+|            |  |       HeartBeat       +<----->+       HeartBeat        |  |            |
+| Primary VM |  +-----------+-----------+       +-----------+------------+  |Secondary VM|
+|            |              |                               |               |            |
+|            |  +-----------|-----------+       +-----------|------------+  |            |
+|            |  |QEMU   +---v----+      |       |QEMU  +----v---+        |  |            |
+|            |  |       |Failover|      |       |      |Failover|        |  |            |
+|            |  |       +--------+      |       |      +--------+        |  |            |
+|            |  |   +---------------+   |       |   +---------------+    |  |            |
+|            |  |   | VM Checkpoint +-------------->+ VM Checkpoint |    |  |            |
+|            |  |   +---------------+   |       |   +---------------+    |  |            |
+|Requests<--------------------------\ /-----------------\ /--------------------->Requests|
+|            |  |                   ^ ^ |       |       | |              |  |            |
+|Responses+---------------------\ /-|-|------------\ /-------------------------+Responses|
+|            |  |               | | | | |       |  | |  | |              |  |            |
+|            |  | +-----------+ | | | | |       |  | |  | | +----------+ |  |            |
+|            |  | | COLO disk | | | | | |       |  | |  | | | COLO disk| |  |            |
+|            |  | |   Manager +---------------------------->| Manager  | |  |            |
+|            |  | ++----------+ v v | | |       |  | v  v | +---------++ |  |            |
+|            |  |  |+-----------+-+-+-++|       | ++-+--+-+---------+ |  |  |            |
+|            |  |  ||   COLO Proxy     ||       | |   COLO Proxy    | |  |  |            |
+|            |  |  || (compare packet  ||       | |(adjust sequence | |  |  |            |
+|            |  |  ||and mirror packet)||       | |    and ACK)     | |  |  |            |
+|            |  |  |+------------+---+-+|       | +-----------------+ |  |  |            |
++------------+  +-----------------------+       +------------------------+  +------------+
++------------+     |             |   |                                |     +------------+
+| VM Monitor |     |             |   |                                |     | VM Monitor |
++------------+     |             |   |                                |     +------------+
++---------------------------------------+       +----------------------------------------+
+|   Kernel         |             |   |  |       |   Kernel            |                  |
++---------------------------------------+       +----------------------------------------+
+                   |             |   |                                |
+    +--------------v+  +---------v---+--+       +------------------+ +v-------------+
+    |   Storage     |  |External Network|       | External Network | |   Storage    |
+    +---------------+  +----------------+       +------------------+ +--------------+
+
 
 == Components introduction ==